Graphic Case Closure on the Crook-Murphy "Bell" Story

By Dr. Henner Fahrenbach

Abstract

Fine linear, crisp details in highly magnified images of the
sasquatch in the Patterson movie of 1967 were recently described
by Christopher Murphy and publicized by Clifford Crook as
evidence of a man-made object, a bell, adhering to the figure.
The explanation resides in imperfect enlargement of an
intermediate printed, screened image. The final image at high
magnification contains artifactual details resulting from the
haphazardly reproduced screen, which was only minimally enlarged.
This finding, a methodological artifact, does nothing to
discredit the authenticity of the Patterson movie.

Introduction

I have in my possession a number of 8x10 pictures, sent to me
by Christopher Murphy for evaluation of the significance and
origin of the bell-like image, described by him and publicized by
Clifford Crook. They were produced by copy machine enlargements
of partial Patterson movie frames reproduced in "Manlike Monsters
on Trial", edited by M. Halpin and M. M. Ames, available from
University of the British Columbia Press. As will become evident,
there is no hint of fraudulent manipulation of the pictorial
material nor willful deception.

I have extracted the magnification of all pertinent pictures
and have calculated the theoretically possible resolution on the
various prints by data from Kodak (see simultaneous posting to
this list). Mr. Murphy has kindly sent me a detailed description
of his methodology.

Common Sense Considerations

As a first approximation, it should have appeared suspicious
(rung a bell, as it were) that a rather crisp detail, the "bell",
should have been visible at about 440x in the Murphy pictures,
which are derived from an image that is decidedly fuzzy at 110x
(the Halpin and Ames picture). That original softness is due
partly to minimal camera and subject motion during the exposure,
but primarily to enlargement well beyond productive levels of
magnification. Thus, plain common sense militates against the
reality of this paradoxical finding. The very fine screen used in
the excellent Halpin and Ames reproductions might seduce the
observer into believing that they are photographs. They are
definitely prints with the usual printer's screen overlaid on
them, a fine grid of dots.

Film Resolution Considerations

The calculation of resolution in the prints (as derived from
the original movie emulsion; see previous post to this list)
produces a value for the smallest resolvable picture element, in
effect a pixel, which is of a size, optimistically, of at least
the entire bell, approximately 2 inches at the level of the
sasquatch. That means that all the details, lines and outlines,
seen in the "bell" image, speak of a film resolving power that
should be approximately ten-fold that stated by Kodak. Obviously,
there has to be a reason for this paradox, since the detail is
there for all to see, and yet the overall image is exceedingly
fuzzy. This resolving power limitation by itself negates the
claimed visibility of teeth, pupil, skin blemishes and
nipple.

Methodological Considerations

The solution of this puzzle lies in the fact that Murphy used
a screened, printed reproduction (at 110x) as the primary source
instead of a photograph. He states in his methodology: "A. My
original photographs of the picture in the Halpin book"
[constitute his source material]. Any picture in Halpin and Ames,
viewed with moderate magnification, shows the screening, a fine
pattern of dots and short lines in several colors and
combinations, as the printing process demands. In many locations,
by happenstance, these dots will produce lines and other
figures.

Consequently, the original information content of the image
has been converted to dots, from which the preceding photographic
image can never be reconstituted. The process of subsequent
copying and reprocessing degrades and alters the image further.
The information content of the image will remain forever
corrupted by the printing step.

Had the printed image had been copied with proper photographic
means, Murphy's final blowups would have displayed a visible,
sharp grid of colored dots, reproducing at most areas of dark and
light shading. In fact, the "bell" is not visible, by Murphy's
own statement, in color prints derived directly from the original
film. However, the copy machine reproduction, with its transfer
of toner and subsequent heat bonding to paper with the inevitable
smearing, is not capable of reproducing the fine screening
pattern, but renders a picture that is deceptively smooth and
photographic in impression. The image content, however, is only
an averaged, smoothed rendition of the dot array.

However, due to random alignments of dots, localized sharp
patterns appear. The reason lies in the fact that the screen,
invisible to the naked eye in the Halpin and Ames frames, was
magnified only 4 times (from 110x to 440x), whereas the partial
sasquatch image shown by Murphy is magnified a total of 440 times
(starting from original film level). Thus, seemingly sharp,
though spurious, detail is incongruously embedded in an image
that shows no substantive features on account of excessive
magnification. Close scrutiny reveals other such random patterns
in his prints, that have the same spurious origin. In fact, much
of the field of Murphy's blowups has a "tweedy" or faintly
cross-hatched look to it, evidence of the diffuse, smeared
remnants of the dot pattern of the source, the screened Halpin
and Ames print.

The next step beyond this level, the "bell" designation, is
due to exuberant interpretation of random features in a manner
reminiscent of earlier "discoveries" of straight and profuse
canals on Mars, all a function of the observer trying to read
significance into noise or imputing reality to random alignments.
The rendering of a drawn bell image with totally imaginary
detail, i. e., ornamentation, is inexcusable and is the only item
in the entire affair that rises dangerously to the level of
"manufacture" of data.

The debacle of the "bell" is due to several factors. As stated
in a previous posting, enlargements for analysis can only be
reliable if made from the original photographic image or at least
an excellent photographic copy. Limits of resolution in any film
can be calculated and applied to prints, but not ignored,
exceeded or circumvented. It is a disastrous methodological
mistake to copy a screened picture and to enlarge it for detailed
inspection. Sub- standard reproduction methods, such as
xerography or copying from a computer screen, compound the
damage. To read significance into noise is human, but it can be
avoided by thorough study of the subject at hand (and, as pointed
out, common sense). The effects of premature publication with
minimal peer review and dissemination to the press can only
produce chagrin on all sides, when the results are eventually
found to be an artifact of the method.

Corrective Considerations

Various double checks would avoid such interpretative fiascos
in the future. For example, the large, commercially available
Dahinden images, at 133x, should also contain the identical
detail in slightly larger format, if it were real. So a
compelling control would have been to replicate the entire
process starting from the Dahinden frames. If these were
xerographically enlarged to the same level as the previous set
(440x), an entirely different image would emerge, since the
Dahinden pictures are also screened reproductions. However, their
screening pattern is of a different geometry, diagonally crossing
lines rather than crisp dots, and different size relative to the
image content. If the "bell" were real, it would show up here as
well, if not better, but enlarged inspection of the pertinent
area only shows an orderly array of screen lines.

Another compelling control for the reality of any image
component can be produced by registered superimposition printing
of a few adjacent, but separate movie film frames onto the same
print. The process will increase contrast and detail of real
structures, which are present in every frame, but will smooth out
photographic noise or grain, which is randomly different in every
image. This option is probably not open to anybody at this stage
nor need it be explored in light of the preceding discussion.

The entire episode should serve as a cautionary example, to
wit, that it is not safe to disregard the customary replications,
controls and critical peer review common to the scientific
process, and that the credulous press cannot serve that purpose.
It provides a warning not to read more into fuzzy images than
common sense suggests is visible.

Patterson Film Resolution

In view of the renewed vigor that the Patterson movie frames
are being examined, I will repost this discussion on resolution
(with verifying recalculation and minimal changes) that went out
about a year ago. Usually such examination is done on prints that
are magnified to or well beyond the limit of profitable
enlargement with the result that the optical "noise" of the
emulsion, usually called the grain, assumes a life of its own and
invites spurious and fanciful interpretations. In order to give
would-be analysts a cautionary yardstick, I provide the following
details and calculations.

The resolution of a film, as stated in Kodak handbooks, is
determined under laboratory conditions, as for example on an
optical bench, by photographing a black and white grating
pattern, meaning 100% contrast modulation, onto the film. If one
uses a grating whose spacing gets tighter and tighter, there is a
point at which the adjacent lines smear into one another and can
no longer be separated. That is the stated resolving power of the
film. This resolving power cannot, of course, be realized under
photographic field conditions, since A) the camera isn't mounted
on a solid pier; B) more importantly, real life scenery does not
have close to 100% contrast of closely adjacent objects, and C)
transfer of the available contrast from scenery to film
(modulation transfer) occurs in an imperfect fashion. However,
contrast contributes in an important manner to the smallest
detail that can be detected in the final print. Additionally, any
part of the intervening optical system, for example the camera
lens, the enlarger condenser (if any), the enlarger lens and the
coherence of the enlarger light source affect the resolution of
the final image and will always degrade it from the optimum
stated for the film. Multiple serial reproductions exacerbate
these problems substantially.

The emulsion that was used by Patterson was, as far as is
known, Kodachrome II. That film has a stated resolving power of
63 lines/ mm. In addition, Nyquists's Sampling Theorem states in
its simplest fashion, that for a signal (minimal image element)
to be detected, you need in effect the space of two lines, which
brings the resolving power to 31.5 lines / mm. Stated
differently, the smallest interval that can reliably resolved
(under optimal conditions) in this film is (1 mm =1,000µm)
divided by 31.5 lines = 31.7 micrometers or microns on the film.
This is the physically limiting value for Kodachrome II, below
which you may see assorted patterns that are part of the
emulsion, but that carry NO image information and are, by
definition, background noise. Advanced image manipulation
techniques can modify contrast, edge sharpness and other aspect
of the image, but cannot generate signal from noise and put the
interpretation at risk.

It will be apparent at this point that all this calculation
can be done without reference to an actual picture. One is
dealing, after all, with a plain physical process that is well
understood and for which the pertinent literature is
voluminous.

The stated resolving power pertains to the original negative.
To find what this value of 31.7 microns corresponds to in the
prints in circulation, one has to know the magnification. When
one does crucially important enlargements, one should print a
transparent millimeter grating directly at the same settings as
the original negative, whereby one generates a reference of the
magnification. Since this is not available, one has to
extrapolate stepwise from the size of an original 16 mm frame (at
1x) and scale it up to the larger images, a process that
accumulates errors but still provides a good "ballpark"
figure.

A good starting point is provided by the images in Perez'
"Bigfoot at Bluff Creek" (1992; BigfooTimes; D. Perez; private
printing. 10926 Milano Ave., Norwalk, CA 90650) He shows a
one-to-one contact print of a bit of 16 mm film for calibration
and a slightly larger image, which includes the frame, at 11.3x.
Beyond that point it becomes necessary to find crisp fiduciary
marks in overlapping pictures of different magnifications to
extrapolate further. Thus, the Dahinden commercial picture of the
full frame No. 352 (wide format) is approximately 37.5 x, the
Dahinden vertical pictures of Frames 323 and 352 are magnified
about 133 times, and the Halpin and Ames pictures are about 110 X
(Manlike Monsters on Trial, University of British Columbia Press,
1980).

Some pictures that have been circulated of Patty's head alone
can be calibrated by the preceding pictures and have been found
to exceed 1,000 fold magnification. For the Patty rear view
pictures, information available from NASI indicates that the
large Dahinden pictures are at exactly a third of the
magnification of the sideviews, i.e., 44 times, the Halpin and
Ames picture 22 X. If one multiplies the maximal possible
resolution that this film allows with the magnification, one
arrives at a value that constitutes the absolute smallest
resolvable detail in the pertinent print. This value will
inevitably be overly optimistic (too small) because one is not
dealing with a stark black-and-white image nor a steady camera.
For the vertical images (Frame 323 and 352) this value is (133 x
31.7 microns) = 4,216 microns, or 4.2 mm. Cut out a paper circle
with this diameter and it will approximate the smallest detail
(optimistically) resolvable, slightly over 2 inches on Patty's
body. (Actual resolution, for the above-mentioned cautionary
reasons is apt to be worse than that, possibly by half) Upon
inspection of this juxtaposition, the resolution in these large
pictures picture is virtually the same as the largest blobs like
the nose and the ear projection, but anything below that level of
detail does not contain information. This maximal resolution is
clearly discernible in the 133 x pictures, which have lots of
empty magnification even though that makes it a little easier to
look at them at a distance.

Thus, there can be no talk about detecting individual strands
of hair, insect bites, skin blemishes, the pupil, teeth or other
similar fine detail. Actually, everything there is to be seen in
the pictures is visible with the naked eye at 50-100x
magnification, i.e., surprisingly, common sense prevails in
"what-you-see-is-what-you-get". Thus, finger or toe detail, that
should lie in the vicinity of this 2" limit, does not show up
crisply at all. Any conclusions based on supposed detail below
the stated limit are largely a function of the imagination of the
examiner, should be viewed with grave suspicion, and would
require heroic proof to be convincing. Analysis based on anything
other than direct copies of the original film frames is also to
be avoided at all cost due to the above considerations.
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